diff options
| author |   Lukas Wunner <lukas@wunner.de> | 2022-09-11 11:24:24 +0200 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-22 16:10:45 +0200 |
| commit | e2752ae3cfc9a486c5af38b302615705992c3a78 (patch) | |
| tree | 60ca60c73b7c7605dc6d50fe5f933513e787363e /drivers/tty | |
| parent | tty: serial: cpm_uart: remove unused cpm_uart_nr declaration (diff) | |
| download | linux-dev-e2752ae3cfc9a486c5af38b302615705992c3a78.tar.xz linux-dev-e2752ae3cfc9a486c5af38b302615705992c3a78.zip | |
serial: omap: Disallow RS-485 if rts-gpio is not specified
The serial-omap driver requires an rts-gpio for RS-485 to work.
Historically it has allowed enabling RS-485 even if no rts-gpio was
specified in the device tree.
That doesn't make any sense, so disable RS-485 on probe if rts-gpio is
missing and disallow user space from enabling it.
Three NULL pointer checks for up->rts_gpiod can be dropped as a result,
simplifying the driver slightly.
Cc: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/f191dcca0d8ea03598c463fc0d3fba8941ff2275.1662888075.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/omap-serial.c | 27 |
1 files changed, 13 insertions, 14 deletions
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index c87d85b901a7..9c4fd0985f3d 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -300,8 +300,7 @@ static void serial_omap_stop_tx(struct uart_port *port) serial_out(up, UART_OMAP_SCR, up->scr); res = (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) ? 1 : 0; - if (up->rts_gpiod && - gpiod_get_value(up->rts_gpiod) != res) { + if (gpiod_get_value(up->rts_gpiod) != res) { if (port->rs485.delay_rts_after_send > 0) mdelay( port->rs485.delay_rts_after_send); @@ -397,7 +396,7 @@ static void serial_omap_start_tx(struct uart_port *port) /* if rts not already enabled */ res = (port->rs485.flags & SER_RS485_RTS_ON_SEND) ? 1 : 0; - if (up->rts_gpiod && gpiod_get_value(up->rts_gpiod) != res) { + if (gpiod_get_value(up->rts_gpiod) != res) { gpiod_set_value(up->rts_gpiod, res); if (port->rs485.delay_rts_before_send > 0) mdelay(port->rs485.delay_rts_before_send); @@ -1336,13 +1335,11 @@ serial_omap_config_rs485(struct uart_port *port, struct ktermios *termios, up->ier = 0; serial_out(up, UART_IER, 0); - if (up->rts_gpiod) { - /* enable / disable rts */ - val = (rs485->flags & SER_RS485_ENABLED) ? - SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND; - val = (rs485->flags & val) ? 1 : 0; - gpiod_set_value(up->rts_gpiod, val); - } + /* enable / disable rts */ + val = (rs485->flags & SER_RS485_ENABLED) ? + SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND; + val = (rs485->flags & val) ? 1 : 0; + gpiod_set_value(up->rts_gpiod, val); /* Enable interrupts */ up->ier = mode; @@ -1547,11 +1544,13 @@ static int serial_omap_probe_rs485(struct uart_omap_port *up, ret = PTR_ERR(up->rts_gpiod); if (ret == -EPROBE_DEFER) return ret; - /* - * FIXME: the code historically ignored any other error than - * -EPROBE_DEFER and just went on without GPIO. - */ + up->rts_gpiod = NULL; + up->port.rs485_supported = (const struct serial_rs485) { }; + if (rs485conf->flags & SER_RS485_ENABLED) { + dev_err(dev, "disabling RS-485 (rts-gpio missing in device tree)\n"); + memset(rs485conf, 0, sizeof(*rs485conf)); + } } else { gpiod_set_consumer_name(up->rts_gpiod, "omap-serial"); } |